Re: [Linux-cluster] |Optimizing DLM Speed

From: Steven Whitehouse <swhiteho redhat com>

To: linux clustering <linux-cluster redhat com>

Subject: Re: [Linux-cluster] |Optimizing DLM Speed

Date: Wed, 18 May 2011 16:31:55 +0100

Hi,
On Wed, 2011-05-18 at 16:14 +0100, Alan Brown wrote:
> Bob, Steve, Dave,
>
> Is there any progress on tuning the size of the tables (RHEL5) to allow
> larger values and see if they help things as far as caching goes?
>
There is a bz open, and you should ask for that to be linked to one of
your support cases, if it hasn't already been. I thought we'd concluded
though that this didn't actually affect your particular workload.
> It would be advantageous to tweak the dentry limits too - the kernel
> limits this to 10% and attempts to increase are throttled back.
>
Yes, I've not forgotten this. I've been working on some similar issues
recently and I'll explore this more fully once I'm done with the
writeback side of things.
> This doesn't scale for larger memory sizes on fileservers and I think
> it's a hangover from 4Gb ram days.
>
> AB
>
Yes, it might well be, so we should certainly look into it. Again
though, please ensure that you raise this through support so that (a) it
doesn't get missed by accident and (b) that we are all in the loop. If
there are not tickets open for these, then we need to resolve that in
order to push this forward,
Steve.